R.J. Cava, B. Batlogg, K.M. Rabe, E.A. Rietman, et al., "Structural anomalies at the disappearance of superconductivity in Ba2YCu3O7-ë: evidence for charge transfer from chains to planes," Physica C, 156, 523-7, 1 November 1988. R.J. Cava (AT&T Bell Laboratories, Murray Hill, N.J.): "The superconductor Ba2YCu3O7-x was a revolutionary material, as it was the first of the now handful of chemical compounds to be superconducting above the temperature of liquid nitrogen. It continues to surprise and stimulate physicists and materials scientists around the world. Over its surprisingly large range of oxygen stoichiometry, the compound is superconducting at 90K and 60K and is an antiferromagnetic insulator. The crystal structure consists of one-dimensional copper-oxygen chains and infinite planes of CuO5 pyramids. Superconductivity occurs in the infinite copper-oxygen planes.
"While analyzing our data for samples of Ba2YCu3O7-x prepared by an unusual low temperature route, we noticed an unanticipated and dramatic jump in one crystallographic ...
